King Louis XVI of France and his queen, Marie Antoinette, were killed during the French Revolution. Their son and heir was said to have died in prison in 1795 but did he in fact escape? The 10-year-old spent his last two years of life in solitary confinement with no human contact. During his final few months he neither talked nor walked, rumours spread that this was an imposter and that the real dauphin had been smuggled out in a laundry basket and replaced with another boy. Years later, dozens of men from all over the world were claiming they were Louis-Charles, the rightful heir to the French throne. It could never be proven one way or the other, but in 2000 a team of scientists took DNA samples from the heart of the boy, which had been recovered and kept in a royal crypt. Claire Bowes has been speaking to professor Jean Jacques Cassiman and historian Deborah Cadbury about the mystery.

(Photo: Illustration of Louis XVII - formally Louis-Charles, Dauphin of France in prison.Credit: Hulton Archive/Getty Images)